DEC 28, 2015 9:54 AM PST

Marijuana Reduces Seizures in Treatment-Resistant Epilepsy

WRITTEN BY: Julianne Chiaet
An outdoor hemp plantation in the UK. This is not the strain used in the study

Almost one-third of epilepsy patients suffer from a treatment-resistant form. Their condition is associated with severe unhealthiness and an increased risk of death. 

The use of medical marijuana to treat epilepsy has generated a great deal of interest among epilepsy patients and their doctors. There is no lack of anecdotal evidence of the drug's benefits and widespread use of treating epilepsy. Some parents have turned to cannabis to treat their child's debilitating epilepsy and found it significantly reduced the presence of seizures. 

There is not, however, a significant amount of scientific literature of back up the claims. 

Principal investigator Orrin Devinsky, M.D., is director of the Comprehensive Epilepsy Center at NYU Langone Medical Center.Neurosurgeon Orrin Devinsky wanted to know more about using cannabidiol to treat epilepsy. Cannabidiol is one of over 60 compounds found in marijuana. It is one of the two compounds found in the highest concentration in marijuana. Cannabidiol doesn’t get the user high. While this makes it a poor choice for recreational users, the medical field is drawn to it for its significant medicinal benefits and minimal side effects. 

Along with a team of researchers, Devinsky found that the medical marijuana derivative was well-tolerated, safe, and  effective in reducing seizure frequency in children and young adults. Thus, the drug might have a sufficient safety profile in children and young adults with treatment-resistant epilepsy. 

The researchers recruited 214 patients with severe, unmanageable, childhood-onset, treatment-resistant epilepsy. The participants, aged 1 to 30-years old, were already receiving stable doses of anti-epileptic drugs. They were additionally enrolled in an expanded-access program at one of 11 epilepsy centers across the United States. Expanded-access programs allow patients to gain access to investigational drugs not yet approved by the FDA.

Both the study participants' families and the researchers knew the patients were receiving cannabidiol. The researchers gave the patients a daily dose of an oral form of cannabidiol called Epidiolex. Participants initially took 2 to 5 mg/kg. Doctors increased the dose up to 25 mg/kg or 50 mg/kg per day depending on the study site. The study took place over a course of one year. They monitored 162 patients for at least 12 weeks. Of the 162 patients, the researchers included 137 patients in the drug effectiveness analysis.

The results showed, on average, a 36.5 percent reduction in monthly motor seizures. The average number of monthly motor seizures fell from 30 at the study’s start to 15.8 over 12 weeks. The seizures were recorded by parents or caregivers in diaries that were reviewed by the study team at each visit. Lab screenings were conducted at the beginning of the study and after 4, 8, and 12 weeks of treatment. 

The cannabidiol proved to be adequately safe and was generally well-tolerated by patients. Adverse events were reported in 128 of the monitored 162 patients. Most of them were mild to moderate and lasted for only a short time. Still, 20 patients experienced serious adverse events. Of those 20, only five discontinued treatment 

There are over 40 types of seizures. The two types of seizures that were reduced the most were focal and atonic seizures. Focal seizures consist of impaired consciousness, altered senses, and repetitious behaviors such as blinks or twitches. Atonic seizures are characterized by a sudden and general loss of muscle tone, especially in the arms and legs, which often causes the patient to fall. 

Two patients were completely free of seizures of all types over the entire 12 weeks. 

These latest findings provide the first estimates of safety, tolerability and efficacy of prescription CBD in children and adults with severe, highly treatment-resistant epilepsy. 

"We are very encouraged by our trial results showing that [cannabinoid] was safe and well-tolerated for most patients, and that seizures dropped significantly," says Devinsky. 

"But before we raise hopes for families who regularly deal with the devastation of treatment-resistant epilepsy, more research, including further studies through our ongoing randomized controlled trial, are needed to definitively recommend CBD as a treatment to patients with uncontrolled seizures."

"I empathize with parents who are looking for answers and will try anything to help their children suffering the devastating effects of intractable epilepsy. But we must let the science, and not anecdotal success stories and high media interest, lead this national discussion," cautions Devinsky. "Taking CBD in a controlled medical setting is vastly different from going to a state where medical marijuana is legal and experimenting with dosing and CBD strains.”

Devinsky is now leading a randomized controlled trial where patients will be randomly assigned to a placebo group of a cannabinoid group. The trial will help determine the specifics effects of the drug and better eliminate research bias.

The study was published in the December 23, 2015, issue of Lancet Neurology

Sources: study via The Lancet, press release via EurekAlert! and NYU Langone Medical Center, Epilepsy Foundation, Epilepsy Foundation of Colorado, CBDForSure


About the Author
Bachelor's (BA/BS/Other)
Julianne (@JuliChiaet) covers health and medicine for LabRoots. Her work has been published in The Daily Beast, Scientific American, and MailOnline. While primarily a science journalist, she has also covered culture and Japanese organized crime. She is the New York Board Representative for the Asian American Journalists Association (AAJA). • To read more of her writing, or to send her a message, go to
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